Stencil coating machine



6 Sheets-Sheet l 'zaries il? Aug. 14, 1945. c. F. scHAEFER STENCILICOATING MACHINE Filed Nov. 18, 1941 Aug. 14,` 1945.

c. F. scHAr-:FER

STENCIL COATING MACHINE 6 Sheets-Sheet 2 I Filed N0v. 18, 1941 Q NVENTOR ATTORNEYS Au@ 14, 1945- c. F. SCHAEFER 2,382,920

STENC IL COATING MACHINE Filed Nov. 1s, 1941 e sheets-sheet s ll I INVENTOR l .BY l

ATTORNE'Y5 Aug. 14, 1945. c. F. scHAl-:FER

1 SIENClLl GATING MACHINE 6 Sheets-Sheet 4 Filed NOV. 18, 1941 ATTORNEYS l Aug. 14, 1945. c; F. scHAL-:FER

STENCIL COTING MACHINE Filed Nov. 18, 1941 s sheets-sheet 5 INVENTOR ATTQRNEYS All@ 14, 1945' jc3. F. SGHAEFER I 2,3@2920 STENC IL GOAT ING MACHINE Filed NOV. 18, 1941 6 Sheets-Sheet 6 2 iufm/nfima@ Z, I Y INyENToR ATTORNEYS Patented Aug. 14, 1945 `Aloo1ioeiioo-Nivembe 18 194i? f N1-0 Claims.

temperatures, or heated or Cooled to prono? Workineieroperelure, end has for en oloieoi' ioiolof` vide euch' o machine with improved and more efloienl;` means for forcing the `riuiizerinl,y throidgiqx the stencil to the article to becpated togive" le morenniform qppliogtion 0I `the moteiial- The coatings can be vopplfiedin spots, ,stripes innegillelr design-s, as Well es full .coverage e eide o f -sheeis- The problems iilvoleii in this lime: of Coating `:ire quite d erent from themimeggmpli machine intended for prilf-iti-ngl purposes with nksx ;t:

Ibis also en object of the. invention io movido a construononwhieh wille-@intein ille iemooifef tulle of the eoatingsolntionat substantial-1y@ the constant :and desiree degree io .miniem the .se-j lution ,at thefprope afndunifrorgn c onsisigericyx` and ibis moy involve oiiliei ooeliiie heetirig. the, s oliution,` but more genenal-lyheoting-- 1t. is o; in -l ther Objet of the nventiorin-to"provideaJ sinapii:` fied Construction, espeoielly. oleiioioliiiee stencil .drum ooereiioe es e oooieiiier for e quantity-oi the coating s ,oiutiorn` Whih may befeasiiyoyjedy and dismantled for` eleaningjpiixposxeslafnl @hnge ine the Sionoil- .Anoihee obieoiie .to movieie improved oonsirooiionend; errerieemeomiierehy e should on miele to` be eeeeeelfoii o eend io the vmachine the stencil` drum `vigili be aintoxnaltioliy Siolooodwith .an imperio-rete poriionet iheloner part-thereof `nel opposite the feeding roll .so the Coating Solution will not ,be fonoedonto the feeding roll. Y

`son .another Objectis to pondeenfo oggi e ment ior uniformly V oeinfing the .coated is/:lee from the maehineet theproner speed izo prevent smudging or irregular application .ofthe oeting ,solntiom and inyolying elmovobleoonveyor operl otedelt .the desired speed.` o e e `Wnh the foregoing and :other b ots I have 4lrleryjseithe eonstruotin illnstijotedint accompanying drewingslioiriningve part of .Speoiiiooiioo 1i. Howeveo is io be L oodereieoo; thatjohe ini/ entiendo .not confined to .the exoot details .and .arrangement Shown; but mayn lode voriooe ohiioeee orio -modiliooiioiiol nl ioiimlie Seepeofgiheieveeoon-- i. f

nino; nosed; "1 (cifioneizny f ggl isef ide'felevotion of themaohiiie with noriehioken'eweiy; I

Figi 23s o detail horizontallseoiion substantially online 2-2lo'frvFg.,l;r"`, l

` Fig'f 3 .iS eri elevaiioiief one mountinefor the pre ssii merel1er;` i j l Eilef1 is e veriieel longitudinal seetion snoeienooliyon une yevi ofi the hood nein; om ted", tolriclwvith various parts broken envoy;

Fgyiso too Dlerwiew, they hood eneiosing the dion 'ondjthleheeeing means V:or th@ @lotion looE `1"ig 6 is a veriioel treheverse Section eufbstarif' iiellii- A on the line ii-fio? Eig. '4; `tiiefiiood leem? :tted; l l" ELF' .Il iieiiveirseleeetion tiilnoiigh the duim ehowirin ihehoodiri eleteiion: Eid eis o; iop pier1 {Doble} L i" Fiel 9 is afi :engi @and `hood eh means; i vf, i f fie- :1" is eoereoeoiiie YieWoioiie-of the elliometie-control'stops'iorfihe feed; i l'jfFig. 1 1fis` periiielweriieoly eiionendpertiel eleeiion heyqriyenieensond eliminatie-icone irol `Si 1owin ii in onore-ove of erro/ine' position @11d M5L: l;

Fig.' 12 is Vsnfiihtr View showing it in released orscoopedposition i sdeviee wasde ,ned piimenly ,for-emile ing relatiyely l henny 1; @ating innterials to notions ift leeor ihetis solutions in semielieufid eoiiolif` io. o1"i sofficigeritiy Yieeoiisto be required io' be ioiced through' iiieeieooil or seinen in being epe plied to filie 'miele .siioh ier exemple as ponen looiheeite end' .eereboeiid mieles. The .matie- Iioloppliod meymrexemnle be edhesvee inelud- 49 ing gloes eiridjsimilor materiels or pest 'either ,clear for` with eiiiginonts `for "ooloxirig purposes; 'eteexemplesbieing 'spot "gluing ,for"d o 1.1;`l. 1.efeeisels.j cardboard oertone, oontai ere, leetheireite eiland Similar @Filiales-Tf1 1 i 'T Ilie {delvioe iiioldesJ-o euiiehlefhese eompiis upright Side' mmbe ,s I eleiiientsI-of .the devi ete` mounted, iiioiufiirieiih'e i:oieteble Stencil( .sinoiriz eho1oSed'.-ir1 a Suitable liood `3 spaced outwenily o Suitable :distance from 59 the drum, "'Ihe' drlimgeomprises la hollowshell hevie o, portion i imerioroieend another por'-v ioifetion'of" e noeieiioi Vthe owing Aone forni; of, heating .be-ery conogrucooos.

"iii Whiolifihe" is preferably made of two sections comprising the body section G closed at one end by th'e wall 1 and a closure 8 at; the other end having flanges 9 telescoping with the open end of the body 8 and secured by any suitable means, such as screws for example, not shown, for easy application and removal. The drum is mounted on suitable rollers I0, there being two of these rollers at each of the opposite ends of the drum and spaced on opposite sidesof thevertical plane through the axis of the drum so that thedrum may be removed by merely lifting it from the rollers. It is rotated by friction from these rollers which are driven by a suitable driving means presently to be described, the rollers preferably being 'rubber covered to give the properl grip on the'drum to frictionally drive it and may have flanges yI lI, at the ends of the drum to maintain the drum in proper position. The pair of rollers on each side of the drum are mounted on a shaft I2 running insultablebearings in the side members I, and the two shafts are'connected togetherfso 'as to be driven at thev same speed by a chain driveK I3 running over 4suitable sprockets I 4 Ion the shafts.

One ofsthese shafts, in the present case 4the shaft onV the outlet side of the drum, is driven througha releasable` frictionclutch I5 which is inv turnd'riven through 'suitable' gears ,I 6 and `I'I from "thehmaindrive shaft I8 driven fromv any suitable source jof power, not shown, by means of Hafsuitable belt I3 running over thepulley 20 nthisshaft. 'The'clutch I5comprises a lfrictionl disc 2| `rotatable with the gearI I6 vand sliding friction member 22,'splinedon the shaft so asto be slidable longitudinally thereon but to drive the` shaft when in engagement with the disc 2I'.` Theg member 22 may be shifted to or from engagement with the disc 2I to drive or stop the drum'by means of a lever 23'having rollers 24 running in a groove 25 in the shiftable element and fpivoted' at 26 on a bracketv 21.- 'I'he upper arm 28' of this lever is located a short distance from one end of the stencil drum 2 ina position to; be'y operated' by an automatic stop mechanism toI shift, the element 2,2 tostop rotation ofthe drum 'under -certainv conditions. The clutch elenienty is'held in the 'on and olf-positions by a spring`29'havin`g recesses or notches 30 and 3| engagingl the lever 23 to hold it in the two posik,

During operation the drumv 2 is rotated counterclockwise as viewed in Figs.' 1, 4 and 7, and on the forward side is a feed table 32 to'support the article 33,;su'ch'for example as la sheet of cardboard or acarton or container in the flat conditionam it is fed by hand between the drum 2 andthe pressure feed roller 34 'u nder the drum ndeiitending' longitudinally thereof throughout so as not to contact the drum to pick up coating solution therefrom, but the spacing is less than the thickness of the article to be coated so that when the article is fed between the stencil drum and the roller the roller is forced downwardly against the pressure of the springs 38, which thus apply pressure to the roller to press the article against the lower side of the stencil drum for the feeding and coating operation.

' The feed and pressure roller 34 is driven from the main drive shaft I8 by a gear 4I meshing with the drive pinion Il mounted on a transverse shaft 42. This shaft carries a sprocket 43 in turn driving a chain 44 running over a sprocket 45 on the shaft 35 carrying the roller 34, the gearing driving this roller and the drum being so proportioned that the surface speed of the roller is the same as that of the stencil drum.

- any suitable number of narrow strips spaced latthe llength of the drum. This feed roller is mountedv on a shaft supported at its opposite endsiinsupporting levezrs`35 pivoted at'31 in the side members I. Yieldable spring pressure is applied to'thisroller bythe coil springs 38 on screws 39. carried by .an arm of thelever 36Y on the opl posit'e iside of the pivot 3T 'and ypassing through t eed'table 3 2; `Adjustable nuts 48 are threade l he screw 39' andl engage the top vof the table '32H'to.liinit* downward movement of the s'crewjand thus limit upward ymovement of the feedjor pressure'roller 34 toward the stencil drum, arfidlthey limit of this movement may be varied' by adju's'ting thejnuts 40. l' They are usually adjusted so'fftliatfwhen there is 'noarti'cle to be coated nett/'ee *the vstenen y dimm and theA roller `:m the roller lspacedv a" short' distance from'the drum erally, and it is driven with a surface speed substantially that of the stencil drum. The drum 48 is mounted on the shaft 42 so that the conveyor is driven from the main drive shaft I8 by thegears I'I and 4I,

The drum 2 forms a' container for aquantity of the coating solution indicated at 49 Fig. 8. The relatively large openings 50 in the end walls of the drum provide easy access to the interior of the drum for feeding-the material'thereto and maintaining the proper amount of the material in the drum. Means is provided submerged in this material for forcing it through the screen and the stencil on the surface of the drum comprising a rubber covered pressure roller 5I extending longitudinally throughout substantially the full lengthV of the drum and engaging-the lower interior. wall of the drum so as to be frictionally driven thereby,'this roller acting as the drum rotates toforce the proper amount of the coating solution through the stencil onto the ar,- ticle to -be coated, passing between the drum and the pressure or feed roller 34. This roller 5I is mounted on a shaft 52 having bearings at its-opposite ends in uprightvstandards 53 secured to a transverse bar` 54. This bar is preferably noncircular and is held against turning but to permit vertical movement by being guided in'upright notches 55 (Fig. 3) in the side members I. A block 56 extends across vover the top of each of these notches and forms an abutment for a spring t51 resting at its other end on the bar 54 and embracing a threaded stud 58 secured to the bar and passing through the block 56 with an adjusting'hand nut 59 threaded on the stud above the block tol adjust the tension of the springwa'nd therefore the Apressure of the roller 5I against the inner surface of the drum 2. The bar 54, extendslongitudinally through the drum and the openings 50 in the end Walls thereof so as to be supported on the side members I. As the openings 50 are of relatively large-size it is preferred to' provide a deflector disc 60 on the inner side ofthe end walls of the drum surrounding this opening yand at its central portion being spaced from the end walls of the drum to prevent the aeeafeeo solution dripping or splashing through the end Gpenngsil fr" I s m. 1...

-Means is f providedi `for-f:maintain-ing the ternperature ofi the 1 'coating l solution substantially constant andl at the-` proper r degree.A4 AThis may comprise `various constru'ctions-I` ori-arrangements to employ various# liieatix-ig 'or 5 cooling mediums such as electricity, steam; 'hot water, oil3or other fluid. it Vcould be an? electric heaterin the drum Zandt immersedl'in the solution, but because with suchan; arrangement the materialimight burn orchar on .theheater it is preferred to use a fluid heater',A such for `example as steam, water or oil', pipes` immersed the coating' solution, as shown in. Figs. I, 2 and 7; at BTI. The arrangement shown comprisesi` a pipe extending longitudinally of the drum immersed in `the solutionin frontier the-"pressure roller 51tr VTwo runs of this pipe are shown, but or cou-rse anynumber may be used as: desired to :secure the proper amount of surf ace for eitherv heating? orA cooling the solution, usually heating being-required" to `maintain it at the properconsistency to be;` forced through the stencil uniformly and at the `proper rate for most satisfactory` resn'llts.:r :The `pipe 61' sconnects` with substantially radiallyentending.` pipes 62 extending upwardlyinA the drum and* passing outward-` lythrough the opening l50fin fone endlof `the drum to a suitable heateror cooler 63. nAs the sc` lution Yis generallyheated the drawing illustrates heating means, but'it will be understood that should the conditions require cooling ofthe solution a cooling `medium canrbecirculated through the pipes 6l .instead of 'a heating medium. 'The heater 6.3" may' contain waterorloil 64 heated by any suitable means,` preferably` an electric heat# ing unit. A65` supplied lfrom any suitable sourcev of current 6B, and the operation of this heater is automatically controlledfbyl a thermostat-` 'I immersed in the liquid to maintain it automatically andruniformlyatA the proper temperature; v Heated liquid is circulated from this' heater to'rth'e pipes 6|` by means of a pumpl driven by'any suitable means such. as' an `electric motor, not `showmand discharging through` a pipe 68 connected to one of the upright` pipes. 6'2. .After passing through tihe submergedA pipe 6I, it` passeszuto the other pipe 62and return pipei69iback to a heater 63; It may be `desirable to` .also supply heat to `the outside of the stencildrum 2 and within the hood 3. Fox-this purposethere maybe; one-or more pipes `lil mounted on the inside ofthe hood in the space between the hood and drum and `extending longitudinally `thereof` having. its ends connected to thepump El and return pipe E9uby thepipes 1t and 'l2fto formi a supply and return for circulationv of' theY heating or cooling medium through the pipes: 101,01` if preferred .an electric heater` 131mountedrxon the innerside of the hood may bek used either Withgand asfa supplement .to

theheater .10 =or instead of :theheater 10,` and controlled f byA the thermostat `andi supplied' y with current from the-source of supply.` These eifectively supplyV heat Sto itheispacelbetween; the hood and drum and to the outside of the` drum,

The means for. automatically stop-ping rotation of the` drum when there is no articlebeing: ted to the; drum and the feed roller comprises a series of stops on the feed table and trip levers operating certaincontrol. mechanism. The stops are shown at 'I Lrnounted on atransverse shaft l5with their free ends 16 located at the inner end of the table immediately. in` front of thelspace between the drum `Land the feed rollerv 34, ,j and a spring 'H- tendsto holdthe. free enjdsflii` inytheir upper po` sitionzprojecting a short distance above .the top surface of the table 32. Assoon asf one sheet 33A passes between the drum and feed roller sofas to passv off ,the ends 16 of these stops, the springs l1 will swing` them `towthe upper position so their upper; ends project a short distancelabove the table, and' as the next sheet 33 is fed forwardly along the' table by the operator its forward edge ,engages these stops,` as shown in Fig.. 4, to hold the sheet in this position until the proper time for feeding itto the drum `for the coating` operation. This time is determined by an autoe matic trip operated by the drum there being a pawllil mountedon the shaft T5, which-when the'stops 'It are in the upper positionV is raised with its free end projecting into the path of move'- ment of a cam 19 carried bythe drum. As the: drum rotates. to bring the stencil over' the feed? roller 34 this cam 1'9 at theproper time "engages thewpawl 18 forcing it forward or cl'ockwisaas' viewed in Fig. 4, and forcing the stops IBdow'nwardly away from the end of the article 33 to release `it and permit it, to be fed between the drum and roller 34; The` drum continues to ro A' tate and with the feed roller 34 to'pass the articles between the 'drumf and rolleras .long as they are fed along the tableby the operatonfthe stops.`

\ 76 being released oneach revolution at the proper time `toperrnit the article toube coated to be fed to the coating position. The coated sheets as they leave this position pass onto the constantly movingiconveyorl and are carried by this coniveyor away from the coating position. at the` proper and uniform speed so that there is no danger of smudging or otherwise marri'ng the coating, the coated` sheets being removed at the free end ofthe conveyor. Y i l As above suggested, improve@ means isv provided for automaticallystopping` rotation of `the 'drum `'i with the imperforate portion 4 thereof onthe bottom or lower sideLvs-h'ould for anyreason a sheet 33 not be fed' tothel machine. This automatic stopi'l comprises a series ofv trip levers 8D mounted on a transverse shaft 8H located under thetable and arranged with their free end'sffto project through openings 82. in the table.. One or more springs 83' secured to the levers and: en# gaging a stop 84 tends to swing these .levers to their upright position with the free ends 'ex-1 tending through the openings 82v and' projecting a short distance above the "top: of the table. Mounted on the shaftfl. is a. lever 84 vconnected to an upright trip .rod 85y mounted.` in a'. guide bracket `lpivoted at 8T to one of the upright sidel the drum at 89 and normally held in its. elevatedv or full line position of Fig. 4 byv acatch Slf pivoted to the head at 9| and having: a hooked end' Q2I to seat in al notch 9-3 or` engageV a shoulder onY the lever 88, a .spring `$4 tending. to swing it to the holding position and hold it therein. The catch 90 `also includes a cam 95 arranged with "its-.path of movement. in alignment with the free endof the triprrod 85 to`V engage the end of this rodzand shift it under certain conditions, but` tomove: by it without tripping it under certain other conditions. The eccentric lever 88 has a camxsurfa-ce 96` (Fig. lllto engage the arm 28 of theV clutch leve;` 23 when this eccentric 88 is released topermit it to drop to the dottedline position of Fig; 41, this movement being limited by asuitable stop 951;. `'Fhaoperation` of thisl device is as follows-:LAS previously indicated, aslong as articles 3-3 are being. fed tothe machine and: there is therefore one of these articles on the feed table 32, it will engage the free ends of the trip levers 80 and hold them depressed or in the position shown in Fig. 4. However, should the operator stop feeding articles to the machine or for some other reason an article is not placed on the feed table at the proper time, the springs 83 would raise the stop levers 80 so that' their free ends will project above the table. This action will swing the free end of the lever 84 upwardly to raise the trip rod 85 so that its free end will be in the path of movement of the cam 85 carriedby the drum. Then as the drum rotates beyond the position shown in Fig. 4 this cam 95 will engage the end of the rod 85 and will force the catch 90 upwardly to remove its free end 92 from the notch 93 to release the eccentric cam lever 88. This lever will therefore fall by its own weight to the dotted line position Fig. 4, and as it does so will engage the arm 28 of the lever 23 which is in the position of Fig. 11 andwill swing this arm tothe left as viewed in this figure, from the position of Fig. 11 to the position of Fig 12. This will shift the movable member 22 of the clutch I5 from the driving plate 2| and will thus disconnect driving connection to the supporting friction rollers of the drum and will stop rotation of the drum. This trip mechanism 88 is so located on the drum 2 that it releases the driving clutch l ata time when the imperforate portion 4 of the drum is the lower side of the drum over the feed roller 34, and therefore coating solution cannot be forced through the drum by the pressure roller 5| when in this position to cause solution to be fed to the surface of the .feed roller. The clutch lever is held in this position by the spring 29 until the clutch is again shifted to the driving position by the operator. When the operator wishes to again start the stencil drum 2 he places an article to be coated 33 on the feed table which forces the trip levers 80 downwardly and also the trip rod 85. He then swings the eccentric trip lever 88 from the dotted to the full line position of Fig. 4 where it is automatically caught and held by the catch 90. He then swings the clutch lever 23 from the position of Fig. l2 to the position of Fig. 11 again setting the drive clutch in operation to start rotation of the drum, which operation is continued until the clutch is again tripped either by hand or by the eccentric lever 88.

A guide for the articles being coated is provided on the top of the feed table 32 so that these articles will all be fed to the drum in proper relation to the stencil. In the present case this cornprises an angle guide 98 mounted on the top of the table to guide one edge of the articles being fed to the machine. It is secured to the table for adjustment longitudinally of the drum by any suitable means such as a clamping screw 99 mounted on the table and passing through an elongated slot |00 in the lug |0| on the back of the guide.

The stencil indicated at |02 made of cloth, rubber, treated paper, etc., is placed over and drawn tightly around the perforated portion 5A of the drum and fastened with screw clamps. If desired there may be a fine metal or cloth screen |03 on the outer Side of the stencil, the stencil, and the screen if used, being clamped to the drum by any suitable means such as clamping bands |04 clamped about the drum and the stencil by any suitable means such as screws, not shown.

To clean the stencil all that is necessary is to release the blocks 56 when the drum and the bar 54 together with the pressure roller 5| may be lifted from the machine by merely lifting it off the supporting rollers l0. Then the head '8 may be removed from the drum permitting removal of the bar 54 and the roller 5| by drawing it out through the open end of the drum. This exposes all parts of the drum so that it may be readily and easily cleaned vand then the roller and its supporting bar 54 may be relnserted in the drum, the removable head 8 placed in position and the assembled drum again mounted on the rollers |0 and the bar 54 secured in position. A suitable amount of coating solution can then be supplied to the drum through the end openings 50 and kept at the proper temperature and consistency indefinitely throughout the entire operation by means of the temperature control elements 6|, 10 and 13. The stencil drum may then be rotated and articles fed to the machine and coated, as above described. This permits uniform and proper coating of the articles regardless of outside temperatures. Especially important features which are believed to be novel are the rotatable stencil drum forming a container for a quantity of the coating solution within the drum and means for maintaining the temperature of the coating solution at the proper degree, and particularly for heating it and thus maintaining it at the proper and a uniform consistency for best and most effective coating oper ations. Another feature is the pressure roller in a rotatable stencil drum forming a container for a quantity of the coating solution, the roller operating in this solution to force it through the stencil to give a uniform coating. Still another feature is the improved automatic stop means for the drum.- Also, so far as I am aware, it is novel to have a continuously operating conveyor to remove the coated article at the proper speed from the rotating stencil drum in this type of machine.

Having thus set forth the nature of my invention, what I claim is:

1. A stencil coating machine comprising a hollow rotatable stencil drum adapted to hold in its interior chamber a quantity of the coating material, a pressure roller within the chamber in the drum at the lower part thereof and immersed in the material to force the material through the stencil, a heater within the drum to maintain the material at the desired temperature, means for retaining the article to be coated against the outer surface of the drum, and means for rotating the drum.

2. A stencil coating machine comprising a hollow rotatable stencil drum forming an interior chamber adapted to hold a quantity of a coating solution, means within the chamber in the drum at the lower part thereof to force the solution through the stencil, a heating pipe immersed in the solution in the drum, means for circulating a heating medium through the pipe to maintain the solution at the desired temperature, means for retaining the article to be coated against the outer surface of the drum, and means for rotating the drum.

3. A stencil coating machine comprising a hollow rotatable stencil drum having a portion of its wall perforated and adapted to carry a stencil, the interior chamber of said drum forming a con. tainer for a quantity of semi-liquid coating solution, a roller within the chamber in the drum extending longitudinally thereof and immersed in said solution at the lower part of the drum to force the solution through the stencil as the drum rotates, means for rotating the drum, and means for retaining the article to be coated against the outer surface of the drum.

4. A stencil coating machine comprising a hollow rotatable stencil drum having a portion of its wall perforated and adapted to carry a stencil, the interior chamber of said drum forming a container for a quantity of semi-liquid coating solution, a roller within the chamber in the drum extending longitudinally thereof and immersed in the solution at the lower part of the drum, means for yieldingly pressing the roller against the inner wall of the drum to force the solution through the stencil as the drum rotates, means for rotating the drum, and means for retaining the article to be coated against the outerv surface of the drum.

5. A stencil coating machine comprising a hollow rotatable stencil drum having a portionof its wall perforated and adapted to carry a stencil, the interior chamber of said drum forming a container for a quantity of `semi-liquid coating solution, a roller within the chamber extending longitudinally thereof and immersed in the solution at the lower part of the drum, said roller pressing against the inner wall of the drum to force the solution through the stencil as the drum rotates, a pipe immersed in the solution at one side of the roller and extending longitudinally thereof, means for circulating a temperature control medium through said pipe to maintain the solution at the desired temperature, means for rotating the drum, and means for retaining the article to be coated against the outer surface of the drum.

6. A stencil coating machine comprising a, hollow rotatable stencil drum in which the interior chamber of the drum forms a container for a quantity of semi-liquid coating solution, means immersed in the solution within the drum chamber Iat the lower part thereof to force the solution through the stencil, a temperature control means immersed in sai-d solution to maintain the solution at the desired temperature, means for rotating the drum, and means for retaining the article to be coated against the outer surface of the drum.

'7. A stencil coating machine comprising a hollow rotatable stencil drum the interior chamber of which forms a container for a quantity of semi-liquid coating solution, means immersed in the solution within the drum chamber at the lower part thereof to force the solution through the stencil, a hood enclosing the drum. and spaced from the outer surface thereof, a heating means located within the space between the hood and the drum to maintain the desired temperature, means for rotating thedrum, and means for retaining the article to rbe coated against the outer surface of the drum.

8. A stencil coating machine comprising supporting rollers, a hollow rotatable stencil drum mounted on said rollers, means for driving the rollers to rotate the drum, said drum comprising a hollow shell closed at one end and a removable cover forming an end Wall for and closing the other end, said end walls each having a large central opening, a bar extending longitudinally through the drum and said openings, means outside the drum for supporting the bar, depending supports carried 'by the bar, land a pressure roller held |by said supports against the inner wall of the drum at the lower part thereof.

9. A stencil coating machine comprising' supporting rollers, a rotatable stencil drum mounted on said rollers, means for driving the rollers to rotate the drum, said drum comprising a hollow shell closed by end walls, a bar extending longitudinally through the drum and said end walls, upright supports outside the drum having upright guides in which the lbar is mounted for vertical sliding movements, depending supports carried by the bar within the drum, a pressure roller held by said supports against the inner wall of the drum atthe lower part thereof, and springs pressing downwardly on the bar to hold said roller against the drum.

10. A stencil coating machine comprising sup-v porting rollers, a rotatable stencil drum mounted a'ble blocks over the guides, springs |between the iblocks and the rbar tending to force the bar downwardly, depending supports carried by the bar within the drum, and apressure roller held by said supports against the inner wall of the drum at the lower part thereof to forcecoating solution in the drum through a stencil on the drum, and said drum, Ibar andpressure roller bein-g removable lb-y lifting from the supporting rollers for disassembling and cleaning.

M CHARLES F. SCHAEF'ER. 

